Carbon filament holder



May-20, 1952 w. F. ELsHoLz 2,597,714

CARBON FILAMENT HOLDER IN V EN TOR.

MIM M@ May 20, 1952 w. F. ELsHoLz 2,597,714

CARBON FILAMENT HOLDER Fneduan. 25, 1951 s sheets-sheet 2 Walter Fred E isha/z INVEN TOR.

BY @n.don

MHLM

May 20, 1952 w. F. ELsHoLz CARBON FILAMENT HOLDER 3 Sheets-Sheet 5 Filed Jan. 25, 1951 Waller Fred E /sho/z IN V EN TOR.

Patented May 20, 1,952

UNITED STATES PATENT OFFICE Claims.

This invention comprises novel and useful improvements in arc lamps and more particularly pertains to improvements in positive carbon holder assemblies.

The present carbon holder assemblies in arc lamps utilize a single positive carbon holder, and when such lamps are used in conjunction with movie projectors, the practice is to utilize only positive carbons which are of sufficient length to permit showing of an entire reel without requiring replacement. Thus, the operators will remove and discard relatively short positive carbon rods when changing reels to permit uninterrupted showing of the reels.

An important object of this invention is to provide a positive carbon holder assembly which will permit successive burning of a plurality of carbons without an appreciable time delay or break in the continuity of the light between successive carbons, whereby relatively short carbons may also be utilized.

Another object of this invention is to provide a positive carbon holder assembly, in accordance with the foregoing object, with a mechanism for automatically eifectuating the shift between one carbon rod and another carbon rod when the first rod has been consumed a predetermined amount, which mechanism will shift the consumed carbon out of operative position.

An important feature of this invention resides in the provision of a pair of carbon holders which are movable along the same path of travel and so constructed and arranged to support positive carbons in parallel relation to each other, with the carbon carried by one holder disposed rearwardly relative to the carbon carried by the other holder, together with a mechanism for shifting the carbon holders laterally of the path of travel thereof to move the consumed carbon out of registry with the negative carbon and shift the new carbon into registry therewith.

Another feature of this invention resides in the provision of a carbon holder assembly, in accordance with the foregoing feature, with a mechanism for automatically actuating the carbon holder shifting mechanism when the forward carbon has been consumed.

Yet another feature of this invention resides in the provision of a carbon holder assembly, in accordance with the foregoing features, with a common drive means for advancing both holders towards the negative carbon, together with a mechanism for automatically disconnecting the forward carbon holder from the drive means when that holder reaches a predetermined position relative to the negative carbon.

A further feature of this invention resides in the provision of a carbon guide for the carbon assembly constructed in accordance with the foregoing features, which carbon guide is shiftable with the carbon holders to properly position the new carbon in registry with the negative are lamp carbon.

Still a further feature of this invention resides in the provision of a carbon support carried by the forward carbon holder for guiding the carbon on the rearwardly disposed carbon holder.

These, together with various ancillary objects I and features are attained by this device, a preferred embodiment of which has been illustrated in the accompanying drawings, wherein:

Figure 1 is a fragmentary side elevational view of the carbon holder assembly;

Figure 2 is a top plan view of the carbon holder assembly;

Figure 3 is a vertical sectional View taken on the plane 3-3 of Figure 2;

Figure 4 is a fragmentary transverse vertical sectional View, taken on the plane 4 4 of Figure 5, through the carbon holder feed screw;

Figure 5 is a fragmentary longitudinal sectional View taken on the plane 5-5 of Figure 3;

Figure 6 is a perspective elevational view of the positive carbon holders;

Figure 7 is a fragmentary end elevational view taken on the plane 1--1 of Figure 1; and

Figure 8 is a schematic wiring diagram of the holder shift actuating mechanism.

Reference is now made more specifically to the positive carbon holder assembly l0 illustrated in the accompanying drawings, and which assembly includes a base l2, positive carbon saddles I4 movably mounted on the base, carbon holder carriages IB mounted on the saddles for movement transverse the direction of movement of the latter, carbon holders I8 carried by the carriages, and a carbon holder shift mechanism 20.

The positive carbon holder assembly l0 has been specifically designed to be utilized in the arc lamp presently manufactured under the trade name of Peerless Magnarc but it is to be understood that the carbon holder assembly may be utilized with other types of arc lamps with but minor changes in the construction of either 111e arc lamp housing or the carbon holder assem- As is conventional, the arc lamp includes a. base frame 22 having a reflector 24 supported on one end thereof, and a negative carbon 26, supported by a negative carbon guide 28, axially of the reiiector.

The positive carbon assembly base I2 includes a pair of end members 3U and 32 and a pair of relatively parallel L-shaped rails 34 and 36 connecting the end members. A saddle slide tube 38 is secured between the end members, adjacent one end thereof, and a feed screw 40 is rotatably journaled between the other ends of the end members. For reasons which will later become apparent as the following description proceeds,

3 the lands on the threads of the lead screw merge with the enlarged end 42 of the screw 40, the diameter of which enlarged end is equal to the major diameter of the lead screw.

A pair of carbon holder saddles |4 may be formed of a single casting and each includes a bridge plate 44 having a pair of lugs 46 and 4B on one end thereof, which lugs are connected by the transversely arcuate member 50 (see Figures 4 and 5). The lugs are each provided with aligned bores 52 whereby the lugs are slidably received on the crests of the threads on the lead screw 40. The other end of the bridge plates 44 are provided with yokes 54 which engage the saddle slide tube 33 whereby the saddles are guided for movement towards and away from the negative carbon 26. A shaft 56 is journaled in each of the members 50, transversely of the feed screw, and a clutch handle 48 is carried by the outwardly extending end of each of the shafts.

A screw follower 60 is secured by fasteners 62 to the arm 64 on the shaft 58 for movement with the latter into and out of engagement with the threads on the lead screw 40. A coil spring 66 is disposed about the shaft 58 and terminally secured to the shaft and to the saddle to yieldingly bias the follower 60 into its thread engaging position. Obviously, the clutch handle 58 is movable to disconnect the saddle from the lead screw, and, as the lands of screw threads merge with the enlarged portion 42, the follower will ride upon the enlarged end and operatively disconnect the saddle from the lead screw.

The bridge plates 44 are each provided with an elongated guide slots 68, the sides of which guidingly engage the elongated block which forms a part of the carbon holder carriage l5. The carriage also includes a carriage plate 12 which is secured to the upper face of the block and overlies the bridge plate 44, and a guide strap 14 which is secured to the undersurface of the block in sliding engagement with the undersurface of the bridge plate. A guide bar 1S is also secured to the undersurface of the block in parallel spaced relation to the edge of the guide strap adjacent the feed screw, to define a passage therewith for the reception of the carriage guide rail 18 which parallels the feed screw. A holder support arm 80 is secured to one end of the carriage plate and extends in parallel overlying relation to the latter, as is best shown in Figure 3. It will be noted that, as the saddles are advanced towards the negative carbon 26 by the feed screw 40, the carriages |6 are laterally guided by the rail 18. Obviously, when the rail is shifted laterally, the carriages will also be shifted laterally without interrupting the advancement of the saddles by the lead screw 40.

In order to maintain the guide rail 18 parallel to the feed screw 40, while laterally shifting the former, there is provided a first link 82 which is pivoted as at 84 to the end 30 of the base, the other end of the link 82 being connected by a pivot 86 to one end of the rail 18. A second link 88 is connected at one end by the pivot 50 to the other end of the rail 13, and the other end of the link 88 is pivoted to the L-shaped rail 34, as by pin S2. The overlapping intermediate portions ofthe links 82 and 88 are recessed as at S4 and 96 respectively and pivotally connected to each other by the pin 98. The ends of the links 82 and 88 which receive the pivot 8E and pin 92 respectively are slotted so as to permit a certain amount of lost motion between the links and their respective pivot pins. As is best shown in Figure 2,

an actuator arm |00 is attached to the guide rail 1S to laterally shift the latter. An L-shaped carbon guide support member |92 is secured to one end of the guide rail 18 and guidingly engages the end 32 of the base |2 as the member |02 is shifted with the guide rail. An adjustable stop |04 carried by the bracket |06 is provided to limit lateral movement of the guide rail and consequently limit shifting of the carriages I6. A lock nut |08 serves to retain the stop |04 in its adjusted position.

The carbon holders I3 each include a base plate H0 which is secured by fasteners ||2 to the support arm t9 and electrically insulated therefrom in any desired manner. A standard ||4 is carried by the base plate and has a notched upper end H6, L-shaped carbon support shoes ||8 being disposed in the notches ||6 and fastened therein by a set screw |20. A block |22 is carried by one end of each of the shoes |8, which block is provided with an upstanding longitudinally extending flange |24 which constitutes a seat for the positive carbon rods |25. .A tube |28 is secured to the side of the block |22 and a clamp rod |30 is disposed in the tube, the upper end of which rod carries a clamp plate |32 which overlies the block |22. A collar |34 having circumierentially spaced apertures |36 in the periphery thereof is threadedly attached to the lower end of the rod |39 and abuts the lower end of the sleeve to positively urge the clamp plate into engagement with the carbon rods |26 as the collar is rotated. A lever |38 is detachably receivable in the apertures |226` to facilitate rotating the collar. Conductors |40 are secured to one end of each of the shoes ||8 as by clamp blocks |42 and fasteners |44, which conductors are otherwise connected to a suitable source of D. C. power in a conventional manner. A carbon support member |48 having a U-shaped seat |48 is provided on the holder I6 nearest the negative carbon 25 to support the carbon carried by the rearwardly disposed holder.

In order to insure proper registry of the positive carbons |25 with the negative carbon 26, there is provided a carbon guide member |50 which is provided with sidewise aligned U-shaped guide notches |52 and |54 in its upper end. As will be noted from a consideration of Figures 2 and 6, the carbon holders are relatively offset so that the carbon carried by the rearwardly disposed holder extends parallel to that carried by the forward holder' and rests upon the support member carried by the forward holder. The notches |52 and |54 are spaced so that they will respectively guide the carbons carried by the forward and rear holders. The carbon guide |50 is vertically adjustably mounted by fasteners |56 in the carbon guide chute |58 which is secured to an insulative plate |60 carried by the carbon guide support member |02. As will be noted, the carbon guide |50 is insulated from the support member |02, and movable therewith as the latter is shifted with the guide rail 18.

A switch |62 is carried by the end 32 of the base |2 and has a switch arm |64 disposed in the path of movement of the resilient actuator finger |66 carried by the forward saddle 44. The switch |62 is electrically connected in series by conductor |63 with a second switch |10 carried by the end 30 of the base. The latter switch |10 is connected by conductor |12 to an alarm |14 which is otherwise connected by conductor |16 to a solenoid |18. The switch |62 is normally open and is closed by the finger |86 as the saddle 44v of the forward carbon holder moves onto the enlarged end portion 42 of the feed screw to thereby operatively disconnect the forward carbon holder from the feed screw. The switch is normally closed so that upon closing of the switch |62, the alarm |14 and solenoid |18 which is connected to the guide rail shift actuator arm |00 are energized to sound the alarm and shift the guide rail. This causes the carriage and the carbon holders carried thereby to also be shifted laterally of the path of travel of the saddles I4 to move the positive carbon carried by the forward holder out of operative registry with the negative carbon and to shift the carbon carried by the rear holder into registry therewith. Obviously, it is necessary to adjust the carbon carried by the rear holder so that the tip thereof is in transverse alignment with the burning end of the carbon carried by the forward holder at the time the carriage is shifted.

The second switch |10 is disposed in the path of movement of the guide rail 18 so as to be opened thereby when the rail reaches its shifted position. This will deactuate the alarm |14 and solenoid |18. Obviously, if for any reason the rail does not shift upon actuation of the solenoid, the alarm will continue to be sounded, thereby signaling the operator.

As is conventional, the feed screw 40 is driven through gears |80 and |82 which are respectively carried by the end of the feed screw and the shaft |84 which is operatively connected to a motor (not shown). The motor is preferably connected in multiple with the arc between the positive and negative carbons, and may be provided with a rheostat to permit variation in the speed of the motor. The motor and control mechanism therefor are well known, and form no part of this invention and accordingly, further description thereof is deemed unnecessary.

From the foregoing, it will be appreciated that there has been provided a carbon holder assembly by means of which a plurality of carbons may be successively disposed in proximity to a negative carbon without an appreciable time delay or break in the continuity of the arc light. Thus, short carbon rods may be positioned in the forward carbon holder to be completely consumed at which time the carriages are shifted by the solenoid to position the auxiliary carbon in operative registry with the negative carbon.

Having described the invention, what is claimed as new is:

i. In a carbon arc lamp including a negative carbon; a positive carbon assembly comprising a base, a first carbon holder mounted on said base for movement towards and away from the negative carbon, a second carbon holder mounted on said base between said first carbon holder and the negative carbon for movement parallel to the path of movement of said rst carbon holder and so constructed and arranged to support a carbon in parallel spaced relation to the carbon carried by'said first holder, common means for simultaneously advancing both of said holders towards said negative carbon, means responsive to a predetermined position of said second holder for operatively disconnecting said first holder from said advancing means, means for selectively shifting said carbon holders laterally of the path of movement thereof to simultaneously move the carbon carried by one of said holders out of registry with said negative carbon and move the carbon carried by the other of said holders into operative registry with the negative carbon.

2. In a carbon arc lamp including a negative carbon; a positive carbon assembly comprising a base, a first carbon holder mounted on said base for movement towards and away from the negative carbon, a second carbon holder mounted on said base between said first carbon holder and the negative carbon for movement parallel to the path of movement of said rst carbon holder and so constructed and arranged to support a carbon in parallel spaced relation to the carbon carried by said first holder, common means for simultaneously advancing both of said holders towards said negative carbon,means responsive to a predetermined position of said second holder for operatively disconnecting said first holder from said advancing means, means for selectively shifting said carbon holders laterally of the path of movement thereof to simultaneously move the carbon carried by one of said holders out of registry with said negative carbon and move the carbon carried by the other of said holders into operative registry with the negative carbon, means responsive to a predetermined position of said second'holder for automatically actuating said holder shifting means.

3. In a carbon arc lamp including a negative carbon; a positive carbon assembly comprising a base, a first carbon holder mounted on said base for movement towards and away from the negative carbon, a second carbon holder mounted on said base between said first carbon holder and the negative carbon for movement parallel to the path of movement of said first carbon holder and so constructed and arranged to support a carbon in parallel spaced relation to the carbon carried by said rst holder, common means for simultaneously advancing both of said holders towards said negative carbon, means responsive to a predetermined position of said second holder for operatively disconnecting said first holder from said advancing means, means for selectively shifting said carbon holders laterally of the path of movement thereof to simultaneously move the carbon carried by one of said holders out of registry with said negative carbon and move the carbon carried by the other of said holders into operative registry with the negative carbon, means responsive to a predetermined position of said second holder for automatically actuating said holder shifting means, a signal actuated in response to a predetermined position of said second holder, and means responsive to shifting of said holders for deactuating said signal and said holder shift actuating means.

4. In a carbon arc lamp including a negative carbon; a positive carbon assembly comprising a base, a first carbon holder mounted on said base for movement towards and away from the negative carbon, a second carbon holder mounted on said base between said first carbon holder and the negative carbon for movement parallel to the path of movement of said first carbon holder and so constructed and arranged to support a carbon in parallel spaced relation to the carbon carried by said first holder, common means for simultaneously advancing both of said holders towards said negative carbon, means responsive to a predetermined position of said second holder for operatively disconnecting said first holder from said advancing means, means for selectively shifting said carbon holders laterally of the path of movement thereof to simultaneously move the carbon carried by one of said holders out of registry with said negative carbon and move the carbon carried by the other of said holders into operative registry with the negative carbon. carbon guide means carried by said second carbon holder for guiding the carbon carried by said first carbon holder.

`5. In a carbon arc lamp including a negative carbon; a positive carbon assembly comprising a base, a rst carbon holder mounted on said base for movement towards and away from the negative carbon, a second carbon holder mounted on said base between said first carbon holder and the negative carbon for movement parallel to the path of movement of said nrst carbon holder and so constructed and arranged to support a carbon in parallel spaced relation to the carbon carried by said iirst holder, means for advancing said holder toward said negative carbon, a carbon guide mounted on said base for guiding the carbons carried by said rst and second holders, and means for shifting said holders and carbon guides laterally of the path of movement of said holders to move the carbon carried by one of said holders out of operative registry with the negative carbon and move the carbon carried by the other holder into operative registry with the negative carbon.

6. In a carbon arc lamp including a negative carbon; a positive carbon assembly comprising a base, a rst carbon holder mounted on said base for movement towards and away from the negative carbon, a second carbon holder mounted on said base between said rst carbon holder and the negative carbon for movement parallel to the path of movement of said rst carbon holder and so constructed and arranged to support a carbon in parallel spaced relation to the carbon carried by said rst holder, means for advancing said holder toward said negative carbon, a carbon guide mounted on said base for guiding the carbons carried by said rst and second holders, and means for shifting said holders and carbon guides laterally of the path of movement of said holders to move the carbon carried by one of said holders out of operative registry with the negative carbon and move the carbon carried by the other holder into operative registry with the negative carbon, a carbon support carried by said second carbon holder for guiding the carbon carried by said rst carbon holder onto said carbon guide.

7. In a carbon arc lamp including a negative carbon; a positive carbon assembly comprising a base, an elongated carriage guide mounted on said base for movement relative thereto transverse the longitudinal axis of said guide, a rst and a second positive carbon saddle slidably mounted on said base for movement parallel' to said guide, means carried by said base for advancing said saddles towards said negative carbon, a carriage mounted on each saddle for movement transverse the direction of movement of said saddles, means slidably connecting said carriages to said carriage guide for movement therewith transverse the direction of movement of said saddles, means for shifting said carriage guide relative to said base to shift, and means responsive to a predetermined position of one of said saddles for operatively disconnecting that saddle from advancing means, a solenoid operatively connected to said carriage guide for laterally moving the same, and switch means for controlling actuation of said solenoid disposed in the path of movement, said one of said saddles t be closed in response to that saddle reaching said predetermined position.

8. In a carbon arc lamp including a negative carbon; a positive carbon assembly comprising a base, an elongated carriage guide mounted on said base for movement relative thereto transverse the longitudinal axis of said guide, a rst and a second positive carbon saddle slidably mounted on said base for movement parallel to said guide, means carried by said base for advancing said saddles towards said negative carbon, a carriage mounted on each saddle for movement transverse the direction of movement of said saddles, means slidably connecting said carriages to said carriage guide for movement therewith transverse the direction of movement of said saddles, means for shifting said carriage guide relative to said base to shift, and means responsive to a predetermined position of one of said saddles for operatively disconnecting that saddle from advancing means, a solenoid operatively connected to said carriage guide for laterally moving the same, and switch means for controlling actuation of said solenoid disposed in the path of movement, said one of said saddles to be closed in response to that saddle reaching said predetermined position, and signal means actuated by said switch means.

9. In a carbon are lamp including a negative carbon; a positive carbon assembly comprising a base, an elongated carriage guide mounted on said base for movement relative thereto transverse the longitudinal axis of said guide, a first and a second positive carbon saddle slidably mounted on said base for movement parallel to said guide, means carried by said base for advancing said saddles towards said negative carbon, a carriage mounted on each saddle for movement transverse the direction of movement of said saddles, means slidably connect-ing said carriages to said carriage guide for movement therewith transverse the direction of movement of said saddles, means for shifting said carriage guide relative to said base to shift, and means responsive to a predetermined position of one of said saddles for operatively disconnecting that saddle from advancing means, a solenoid operatively connected to said carriage guide for laterally moving the sume, and switch means for controlling actuation of said solenoid disposed in the path of movement, said one of said saddles to be closed in response to that saddle reaching said predetermined position, means responsive to shifting of said carriage guide for deactuating said solenoid.

10. In a carbon arc lamp including a negative carbon; a positive carbon assembly comprising a base, an elongated carriage guide mounted on said base for movement relative thereto transverse the longitudinal axis of said guide, a iii-st and a second positive carbon saddle slidably mounted on said base for movement parallel to said guide, means carried by said base for advancing said saddles towards said negative carbon, a carriage mounted on each saddle for movement transverse the direction of movement of said saddles, means slid-ably connecting said carriages to said carriage guide for movement therewith transverse the direction of movement of said saddles, means for shifting said carriage guide relative to said base to shift, and means responsive to a predetermined position of one of said saddles for operatively disconnecting that saddle from advancing means, a solenoid operatively connected to said carriage guide for laterally moving the same, and switch means for controlling actuation of said solenoid disposed in the path of movement, said one of said saddles to be ciosed in response to that saddle reaching REFERENCES CITED said predetermined position, mea-ns responsive I to shiftigfof said carriage guide for deactuathf rgggeferens are of record in the ing said"'zso1enoid, and means for adjustably iimitingl'shifting of said carriage guide. j UNITED STATES PA'I'ENTS Number Name Date WALTER FRED ELSH0LZ- 1,083,658 Honey Jan, s, 1914 2,097,767 McAuley et al. Nov. 2, 1937 

